Golf practice device



July 14, 1959 G. SI'MJIAN 2,894,752

GOLF PRACTICE DEVICE i Filed Jan. 7, 1955 I 4 Sheets-Sheet 1 COMPUTER 5 i7 Projector T r20 3 \G. 2 37 x F ,45 FIG. 5

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cow PRACTICE nsvxcz: Filed Jan. 7, 195a 4 Sheets-Sheet 2 (FIG. 4

' INVENTOR LUTHER e. SIMJIAN ATTORNEY July 14, 1959 G SIMJIAN I 2,894,752

GOLF PRACTICE DEVICE Filed Jan. 7, 1955 4 Sheets-Sheet a M M x Y SCREEN l l5l" 47 IB I7 152 MI CAMERA LUTHER G. SIMJIAN INVENTOR ATTORNEY July 14, 1959 L. .G. SIMJIAN 2,894,752

I com PRACTJICB DEVICE Filed Jan. 7, 1955 Y 4 Sheets-Sheet 4 T0 emu OF TO ANODE OF TUBE 41 F 8 TUBE 41 V INVENTOR LUTHER G. SIMJIAN ATTORNEY United States Patent ce g My GOLF PRACTICE DEVICE Luther G. Sirnjian, Greenwich, Conn., assignor to The Reflectone Corporation, Stamford, Conn., a corporation of Connecticut Application January 7, 1955, Serial No. 480,529

4 Claims. (Cl. 273-185) This application is a continuation-in-part of application Serial No. 390,061, filed November 3, 1953, now abandoned.

The invention has particular reference to a display device for showing the approximate path a missile would take in free flight, the missiles course being determined from positioning information on a target as the missile traverses a rather limited distance.

Many measuring devices have been devised for determining the path of a missile, some of which use a captive ball and some of which use a free ball with various designs of targets. All these devices are for use within a restricted space so that the action may take place indoors. Prior measuring devices such as golf games have all suffered from the absence of an adequate indicating device for giving the player precise information regarding the results of his efforts. The present invention uses a free ball to more closely approximate natural propelling conditions and in addition employs a target against which the free ball is driven, the target being adapted to provide signals for use in a computing circuit which in turn may actuate a projector device operating in conjunction with a viewing screen.

One of the objects of this invention is to provide an improved target means for a missile which avoids one or more of the disadvantages and limitations of prior art devices.

Another object of this invention is to provide an improved target construction which impedes forward motion of the missile and 'which generates signals for use by a computing circuit.

Another object of the invention is to enable a golfer to attain proficiency in driving by practicing indoors and seeing the result of his stroke if the ball had been played outdoors.

The invention comprises a target means formed by an area which is adapted to receive a propelled missile and impede further forward motion of the missile. The area is provided with two substantially coplanar sensing arrays disposed at substantially ninety degrees to one another for determining the position of impact of the missile on the target in two planes. Each array includes a plurality of fluid charged resilient elongated sensing elements. For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.

Fig. 1 is a side view showing the main components of the golf practice device.

Fig. 2 is a front view of the sensing device which consists of a plurality of flexible tubes mounted in crossed relationship and arranged to operate a bellows to make an electrical contact when struck by a ball.

- Fig.- 3 is a cross sectional view of a few of the tubes shown in Fig. '2 and is taken along line 3-3 of that fig r Fig. 4 is a schematic diagram of connections of a computer system and includes parts of a target and motors which control the display device.

Fig. 5 is a plan view, with some parts in section, showing the details of a light projector which is controlled by three motors and projects the image of a ball on a viewing screen.

Fig. 6 is a side view, with parts broken away, of an alternate form of display device which employs a moving stylus and a moving paper tape.

Fig. 7 is a front view of the viewing screen on which the image of a ball is projected and shows the picture of a golf course as seen by a player standing at the tee.

Fig. 8 is a schematic diagram of connections of a resetting circuit which may be used with the motors to run them back to their zero position. i

Referring now to Fig. l a base 10 holds a tee 11 and a ball 12 in a position for driving. This structure is designed especially for golf practice but it will be evident from the description which follows that a similar combination of switches and targets may be used for measuring the speed and direction of thrown or batted baseballs or of any other propelled missiles. Underneath base 16 and secured to it is a pair of contacts 13 which is operated as soon as the ball 12 is driven from the tee. The operation of these contacts is communicated to a computer circuit 14 which uses the change in current to transmit a signal which is used to determine the velocity of the missile. The ball 12 is propelled by a club generally in the direction which is shown by the arrow 15 and moves against a target means 16 which records the balls horizontal and vertical positions. These two values are delivered to the computer 14 and after suitable computing processes the results are applied to the control system of a projector 17 causing the projector to move and to show the trajectory of the missile on a viewing screen 18 by means. of a light beam 20 which is focused to a small spot on the screen and which represents the missile. The screen 18 may be about 20 feet from the tee.

Fig.2 shows the target system for sensing the horizontal and vertical positions of the missile as it arrives at the plane of the target. Since this target requires a backing plate the missile cannot pass through but is stopped by the target structure. The device comprises a plurality of fluid filled flexible tubes 37 arranged in a vertical position and a similar plurality of horizontal tubes 38 positioned immediately back of the vertical tubes. Fig. 3 shows a section taken through part of Fig. 2 and shows the position of the backing plate 40, the position of the horizontal tubes 38, and the relative position of the vertical tubes 37. Each of the tubes is sealed at one end and fastened to the backing plate 40. The other ends of the tubes pass through a wall 41 and are connected to bellows 42. At the free end of each bellows a contact point 43 is mounted and immediately adjacent to it is a co-operating contact 44 mounted on a second wall 45. When a missile of any type strikes the target at least two of the tubes will be collapsed by the force of the impact. When the tubes collapse one of the bellows 42 in the horizontal array will be extended and contacts 43 and 44 will be closed thereby sending a voltage pulse to the computing circuit. In like manner one of the bellows in the vertical array will close its contacts and another voltage pulse will be sent to the computing circuit.

The computing circuit is shown in Fig. 4 and comprises a target array 46. The ball 12 on its tee 11 operates contacts 13 when it is driven from its starting position and this action causes the sequential operation of relays A and B. When the ball strikes target 46 it makes two contacts which are connected to voltage divider 30 and voltage divider 31. Also at this time, a pulse is sent through am'-' plifier tube 47 which operates relay C. Closing a contact associated with the vertical sensing means in target 46 causes a voltage to be impressed on either one of capacitors 48 and t) and thereby causes current to fiow through amplifier tubes 51 and 52 and sends a modulated current through winding 53 or 54 to operate the armature of a motor 55. This motor is mechanically coupled to the projection system and moves it to the right or left indicating the motion of the ball on viewing screen 18.

The details of the circuit will now be described by considering its operation. When contacts 13 are closed current from the battery 56 flows through the contacts, through the A relay, causing its three contacts to be closed, and then through closed contacts associated with reset button 103 and the normally closed contacts 57 on the C relay to ground. When the A relay is operated one set of contacts 53 closes and locks the relay in its operated condition even though contacts 13 may be opened again. This locking circuit may be traced from the positive terminal of battery 56 over conductor 60, through contacts 58 of the A relay, the A relay winding, contacts 103 and 57, and ground. At this same time contacts 65 are closed impressing a kilocycle alternating current on amplifier tube 66; and contacts 63 are closed thereby actuating the B relay, closing contacts 67 and permitting capacitor 68 to be connected to the control electrode of amplifier tubes 69 and 70.

The result of the above described operations is to make amplifier tubes 66, 69, and 7t} conducting for as long a time as capacitor 68 retains the charge impressed upon it by battery 71 operating through previously closed contacts 72. A small percentage of this charge leaks to ground through resistors 73 and 74 but the capacitor is discharged at a considerably greater rate by the current which passes over conductor 75 through the anode-cathode circuit of amplifier tube 66. This latter discharge path is open only for the duration of the passage of the missile from the tee to the first sensing means 4-6 and therefore the time of rapid discharge of capacitor 68 is dependent upon the speed of the missile.

When contacts 67 are closed amplifier tube 69 is made conducting and current flows from its anode through the Winding of relay D to close contacts 79 and apply alternating current power to windings 95, 98, and 84 of the three motors 55, 97, and 83.

When the ball 12 reaches the sensing device 46 and closes one of the contacts 25 associated with voltage divider 3i) capacitor 76 will be charged through rectifier 7'7 to a voltage which is proportional to the vertical distance of the contact from the bottom of the sensing frame. The control electrode in pentode 47 is biased by battery 78 so that under normal conditions no current flows through the tube and there is no current in conductor Bil. When capacitor 76 is charged to a positive potential, pentode 47 passes current which is modulated by another control elec trode connected to a source of alternating current 81. This arrangement sends alternating current through conductor 80 to winding 82 of motor 83. This motor also contains Winding 34 which is supplied with alternating current through contacts 79 of relay D. The motor 83 is arranged so that it will turn only when both windings 82 and 84 are passing alternating current and therefore, when the modulated current in winding 82 is reduced to zero the motor slows down and stops. This motor is connected to an iris diaphragm and the action results in a closing of the diaphragm, thereby reducing the size of the projected spot on the viewing screen and simulating distance.

Whenever the amplifier tube 47 is in its conducting condition, a voltage is present on conductor 8h which is communicated by means of conductor 35 to the C relay which operates and opens contacts 57. This action opens the locking circuit of the A relay which is then normalized. However, both the B and D relays remain in operated condition because relay B receives current over conductor 60, through closed contacts 102 and 61; and the D relay is actuated by tube 69, made conducting by voltage from resistor 73. As soon as the A relay is normalized 4 contacts 65 are opened and current from the 10 kilocycle source 86 will be broken and tube 66 will be again rendered nonconducting.

When the missile strikes target 46 it closes one of the contacts associated with the voltage divider 31. If the ball should happen to strike the central sensing element and close the central contact nothing will happen because then current flows through this contact, through resistor 87, to the ground connection. However, if the missile is directed to the right or left some other contact is closed and a charge will be impressed through either one of rectifier units 83 or 96 to the control electrodes of either one of the amplifier tubes 51 or 52 and such action will render either one of them conducting until the charge on its associated capacitor 48 or leaks off through resisters 91 or 92. During the time the tube is conducting, current will flow over conductors 93 or 94, such current being modulated by the cycle source 81 since it is connected to a control electrode in each tube and the modulated current will fiow through winding 53 or 54 of motor 55. This motor has a third winding 95 which is supplied with alternating current and therefore current in either one of windings 53 or 54 will cause the motor to turn to the right or left. Motor 55 is mechanically connected to the projector to move it to the right or left thereby moving the projected spot in a similar direction.

When tube 47 was made conducting it delivered a modulated current to winding 82 of motor 83 which caused a spot on the screen to decrease in size from an original maximum diameter to a smaller size which depended upon the magnitude of the charge applied to capacitor 76. This same modulated current is delivered to field winding 96 of motor 97 which is connected to the motor and arranged to move the projector and spot upwardly. Motor 97 also contains a field winding 98 which receives alternating current when relay D is operated. The action of field winding 96 is to move the spot upwardly on the screen at a grandually decreasing speed. In order to move the spot down again, a third Winding 1% is mounted in motor 97 to simulate the balls path. Winding 100 is connected to the anode of amplifier tube 101 which is an inversion device. The control electrode of tube 101 is coupled to the anode circuit of tube 70 which receives its control potential from capacitor 68 through the coupling of voltage divider 73, 74. As capacitor 68 loses its charge the current through the anode circuit of tube 76 diminishes at an ever increasing rate, but the control electrode of tube 161 is coupled to the anode circuit of tube 70 and has the reverse effect, its anode current being increased steadily from a very small initial value. The current in winding lltltl causes the motor to turn so as to bring the spot down and the result of these two actions is, the current from tube 47 through Winding 96 causes the spot to first rise at a decreasing rate and then, current through tube 101 and winding 100 causes the spot to come down at an increasing rate.

The schematic circuit diagram in Fig. 4 shows no means of resetting the motors to their original position so that a second measurement and trajectory showing can be made. Reset buttons 102 and 103 break the locking circuits in the relays and normalize the relay circuits but the motors must be reset by hand by mechanically disengaging the gear coupling between the projector mechanism and the motor armatures to bring the projector back to its starting position. If it is desired to employ a circuit which will do this electrically the reset circuit shown in Fig. 8 may be employed. In this diagram of connections motor 83, having windings 82 and 84, is indicated with two cam wheels secured to the armature shaft. The zero position is shown in the figure with cam 1M holding its contacts 105 in an open position and cam 106 in a position where its contacts 107 are open. Two relays 1G8 and are employed for this resetting operation. Relay 108 when operated closes three contacts, one pair of contacts 111 being in series with a circuit which may be traced from a positive source of potential 112, through contacts 105, then through contacts 111, contacts 107, relay winding 110 and ground. A second set of contacts 113 is in series with a ground connection and a conductor which runs to the control grid of tube 47 (this conductor not shown in Fig. 4). A third set of contacts 114 acts as a locking circuit and keeps the relay in its actuated condition until the motor is fully reset. The reset circuit is placed in operating condition by manually depressing button 115 which closes contacts 116 and connects the positive potential source 112, through contacts 105, through the winding of relay 108, contacts 116, to ground. As soon as contacts 116 are closed relay 108 will be operated if the motor has moved from its zero position and contacts 105 are closed. After the relay actuation contacts 114 provide a path from the ground connection through the relay to the positive potential source. Contacts 113 in applying a zero potential to the control electrode of amplifier tube 47 cause it to conduct and send a modulated current over conductor 80 and through winding 82 thereby turnthe motor in a direction which will bring it back to zero. The above described action occurs when the motor has moved in a counter-clockwise direction and contacts 107 are not closed. If the motor had moved in the other direction causing cam 106 to close contacts 107 a current would have then been sent from the positive supply 112 through contacts 105, then through contacts 111, contacts 107, relay winding 110, and ground. This action causes contacts 117 and 118 to transfer from their upper to lower contact points and reverse the current in winding 84 of motor 83, thereby causing the motor to turn in an opposite direction. As soon as the motor reaches its zero position cam 104 opens contacts 105 and the power source 112 is disconnected.

Motors 55, 97, and 83, which receive their controlling currents from the computing circuit, may be coupled in a number of ways to a display system to show the path of a ball or missile as viewed from the starting position or as viewed from a position at right angles to the horizontal direction of the missiles path. Fig. shows one schematic arrangement of coupling these motors to a projection system 17. The system includes a source of illumination 141, a condensing lens 142, an iris 143', and a projection lens 144 which focusses the image of the iris on the viewing screen 18.

Motor 55 is responsive to the direction of the struck missile and controls a base 145 to move to the right or left by means of a shaft 146 and a screw 147 coupled to an extension of the base. The base 145 is adapted to turn about a vertical bolt 148.

Motor 83 is controlled by the velocity as determined by the computing circuit and acts to decrease the size of the balls image to give the illusion of distance. Shaft 150 is coupled to the iris diaphragm and closes its opening during the computing time of flight of the free ball.

Motor 97 is responsive to the control currents sent by the computing circuit and turns a shaft 151 and a worm screw 152 to rotate nut 153 on threaded bolt 148. The motion is first in a direction to elevate the balls image on the screen 18 and then to lower it to the ground level. If there were no other controlling forces or currents, motor 97 would move the projector 17 to move the balls image up on the screen and then down to a level below the bottom border of the screen. Since the cup is generally shown in the middle of the viewing screen, as indicated in Fig. 7, this movement of the image gives a false and erroneous results. To alter the result so as to produce a more realistic showing, a gear coupling 154 is provided so that the motion of shaft 150 is transferred through a gear differential 155 to subtract a portion of its motion from the rotary motion of motor 97. The result of this controlled action is to elevate the image of the ball and then drop it until it stops some- 6 where on the screen surface, indicating the final position of the ball on the fairway. In order to show the balls distance from the tee a series of arcuate lines 156 (Fig. 7) are drawn on the screen picture with distance designations and the final position of the image shows an approximate value of the length of drive.

A permanent record of the balls flight may be made by a camera 157, the shutter of which is opened before the ball is struck and closed after the image comes to rest. For this purpose a shutter operating device may be electrically coupled to the D relay in series with contacts 79.

An alternate display device which shows the entire trajectory, drawn by a stylus 160 on a strip of paper 161, is shown in Fig. 6. In this arrangement a base 162 supports a moving strip mechanism 163 which is controlled by motor 83, mounted under the base. The paper strip is provided with a calibrated scale 164 which may be in yards or any other distance units. At the start; the zero line is adjusted to be at the stylus point. Then when the ball is struck motor 83 moves the paper in accordance with the recorded velocity value and motor 97 moves the stylus 160 up and then down to trace a complete trajectory 165 as indicated. Motor 97 may be coupled to the stylus by a worm screw 166 and lever arm 167.

While there have been described and illustrated specific embodiments of the invention, it will be obvious that various changes and modifications may be made therein Without departing from the field of the invention which should be limited only by the scope of the appended claims.

I claim:

1. A target construction for a golf practice device or similar apparatus comprising; a target area adapted to receive a propelled missile and impede further forward motion thereof; said target area provided with two substantially coplanar arrays disposed at substantially ninety degrees to one another for determining the position of impact of the missile on said target in two planes; each array including a plurality of fluid charged resilient elongated sensing elements; each of said elements coupled to electrical circuit means which are actuated in response to the displacement of fluid in said sensing elements upon impact of the missile thereby producing actuation of electrical circuit means in two planes in response to the impact position of the missile on the target and said electrical circuit means connected to controlled instrumentalities.

2. A target construction for a golf practice device or similar apparatus comprising; a target area adapted to receive a propelled missile and impede further forward motion thereof; said target area provided with a horizontal and a vertical array disposed at substantially ninety degrees to one another for determining the position of impact of the missile on the target in the horizontal and vertical planes respectively; each array including a plurality of fluid charged resilient elongated sensing element; each of said elements coupled to electrical circuit means which are actuated in response to the displacement of fluid in said sensing elements upon impact of the missile thereby producing actuation of electrical circuit means in two planes in response to the impact position of the missile on the target and said electrical circuit means connected to controlled instrumentalities.

3. A target construction for a golf practice device or similar apparatus comprising; a target area adapted to receive a propelled missile and impede further forward motion thereof, said target area provided with two substantially coplanar arrays disposed at substantially ninety degrees to one another for determining the position of impact of the missile in the horizontal and vertical plane respectively; each array including a plurality of fluid charged resilient elongated sensing elements; each,

of said elements coupled to an associated electrical circuit means disposed'outside of the sensing area and said circuit means being actuated in response to the displacement of fluid in the associated sensing element thereby producing actuation of electrical circuit means in two planes in response to the horizontal and vertical impact positions of the missile on the target and said electrical circuit means connected to controlled instrumentalities.

4. A target construction for a golf practice device or similar apparatus comprising; a target area adapted to receive a propelled missile and impede further forward motion thereof; said target area provided with two substantially coplanar arrays disposed at substantially ninety degrees to one another for determining the position of impact of the missile in the horizontal and vertical plane respectively; each array including a plurality of fluid charged resilient elongated sensing elements; each of said elements coupled to an associated electrical circuit means disposed outside of the sensing area and said circuit means being actuated in response to the displacement of fluid in the associated sensing element thereby producing actuation of electrical circuit means in two planes in response to the horizontal and vertical impact positions of the missile on the target, each of said sensing elements comprising a hollow fluid filled tubing which is closed at one end and is equipped at the other end with an exp-ansible bellows the motion of which actuates the electrical circuit means, and said electrical circuit 10 means connected to controlled instnimentalities.

References Cited in the file of this patent UNITED STATES PATENTS 1 780,896 Michel Jan. 24, 1905 5 2,743,929 Smith May 1, 1956 FOREIGN PATENTS 26,257 Great Britain "1910 118,633 Great Britain 1919 

